Factors associated with treatment duration from start of second-line ramucirumab plus paclitaxel or nab-PTX for advanced gastric cancer: real-world evidence from Japanese Claim Database.

Abstract

177 Background: Recently, the value of RWE has been recognized to be important. We investigated the first line(1L)-2L therapy(Tx) sequence for AGC and factors associated with whole treatment period after RAM plus(+) (nab-)PTX therapy using RWE in Japan. Methods: This study used a hospital-based claims database in Japan. Patients who were diagnosed with GC and started 1L Tx between Jun 2015 and Jul 2019 were selected. The 1L Tx was defined as fluoropyrimidine(FP)+platinum (with or without trastuzumab[Tmab]), and defined to be discontinued when it was suspended for >90 days or switched to different antitumor drugs (2L Tx). In patients who started RAM+(nab-)PTX as 2L Tx, factors associated with overall Tx duration (from start of 2L Tx to the last dose of chemotherapy including subsequent Tx) were explored by Cox regression analysis. Results: 10581 patients (mean age 67.9 years, male 73.9%) received 1L Tx (9024 patients without Tmab and 1557 patients with Tmab). In patients who discontinued 1L Tx, the proportion of 1L-2L Tx transition was 61% (4509/7443) without Tmab and 68% (849/1245) with Tmab. Among 5358 patients who received 2L Tx, 3650 patients (68%) received RAM+(nab-)PTX. The median overall Tx duration was 6.7 months after initiation of 2L Tx with RAM+(nab-)PTX. Factors positively associated with the overall Tx duration from initiation of 2L Tx with RAM+(nab-)PTX were Tmab use before data cutoff (Sep 2019; hazard ratio [95% CI] 0.9 [0.79-1.00]), previous oral FP (0.7 [0.54-0.89]), duration of 1L Tx >150 days (0.8 [0.74-0.87]). Factors negatively associated were peritoneal metastasis or ascites (1.3 [1.17-1.40]), comorbidities e.g., edema (1.3 [1.07-1.45]), renal disease (1.1 [1.01-1.30]), diabetes (1.1 [1.01-1.22]), previous oxaliplatin (1.2 [1.09-1.30]), and rehabilitation (1.9 [1.67-2.24]) or nutritional intervention (1.5 [1.34-1.68]) within 1 month before and after starting 2L Tx. Conclusions: Many of the patients received RAM+(nab-)PTX as 2L Tx regardless of Tmab. This large-scale RWE demonstrated that Tmab use, oral FP, and long 1L Tx duration were associated with longer treatment course from start of 2L RAM+(nab-)PTX therapy.